Process and device for tilting a continuous strip of containers made from heat-formable material

ABSTRACT

In the process, a strip of containers made of a heat-formable material is guided through a deviated course in a transversal direction with respect to a main horizontal line of advance, in which the strip of containers undergoes, in sequence, a first rotation of a quarter of a full turn about a vertical-axis first guide, a first twist by half a full turn, a second rotation, by half a full turn, about a second guide having a winding axis which is parallel to the line of advance, returning towards the line of advance, a second twist by another half a full turn, and finally a third rotation about a vertical axis third guide. With this process, the longitudinal extension of the line of advance is reduced.

TECHNICAL FIELD

Specifically, though not exclusively, the invention is usefully appliedin the field of a system for heat-forming, filling and sealing plasticcontainers made from strips of heat-formable material. The containerscan be used for packing various substances (cosmetics, detergents,pharmaceutical or food products, etc.) either in liquid or solid form,either coherent (pastilles, tablets, suppositories) or loose (powder orgranules).

BACKGROUND ART

Particular reference is made to a process according to the preamble ofthe first claim.

A process of this type is already known, according to which a continuousstrip of containers, for reasons connected to the production process,has to be tilted by 180° by means of a twisting of the strip on itselfabout a rotation axis coinciding with the advancement direction of thestrip towards the filling station. As the flexibility of the strip islimited, mainly due to the presence of containers which confer a certainrigidity on the strip, the angle of twist of the strip cannot be toohigh, so the total 180° turn is developed over a relatively long tracton the line of advancement of the strip itself. This leads to aconsiderable overall lengthening of tie advancement line, with aconsequently large machine length.

The main aim of the present invention is to provide a process whichenable the container-strip advancement line to be reduced overall.

An advantage of the invention is that it provides a process whichenables the longitudinal development of the advancement line of thecontainer strip to be reduced.

A further advantage consists in the fact that the process can berealised with constructionally simple and economical means.

These aims and advantages and more besides are all attained by thepresent invention, as it is characterised in the appended claims.

Further characteristics and advantages of the invention will betteremerge from the detailed description that follows of a preferred butnon-exclusive embodiment of the invention, illustrated purely by way ofa non-limiting example in the accompanying figures of the drawings, inwhich:

FIG. 1 is a perspective view of a tilting device made according to theinvention;

FIGS. 2 and 3 are two sections, respectively according to lines II-IIand III-III of FIG. 1;

FIG. 4 is a detail of the tilting device of FIG. 1.

DISCLOSURE OF INVENTION

With reference to the above-mentioned figures, 1 denotes in its entiretya device for tilting a continuous strip of containers made of aheat-formable material, formed by means of a coupling of two or morecontinuous strips of heat-weldable plastic material.

The device 1 is inserted in a machine for forming, filling and sealingcontainers made of heat-weldable material. The machine, of known type,comprises:

a feed line of two facing strips of heat-weldable plastic material;

a welding station in which the strips, oriented with a flat partvertically arranged, are welded at predetermined zones to produce twoparallel and opposite lines of cells, each provided with an openingarranged on one of the opposite longitudinal edges of the strips, sothat the apertures of the upper line face upwards and the apertures ofthe lower line face downwards;

a forming station in which a forming fluid under pressure is injectedinto the cells through the apertures, in order to expand each cellinternally of a respective forming cavity so as to form a container.

The parts of the machine described up to here, arranged upstream of thetilting device, are of known type and are consequently not illustrated.The machine also comprises, downstream of the tilting device 1, a filingstation for the containers, followed by a sealing station: both of thesestations are of known type and are not illustrated. In the fillingstation, the containers can be filled with various types of products,for example liquid substances destined or not for solidification, orsolid loose substances, in grain or powder form, or objects destined toenter in one piece into the containers, or even objects destined toremain partially outside the containers (for example handles).

FIG. 1 schematically illustrates a cutting device 2 which cuts intohalf, in a longitudinal direction, a strip 3 of containers arriving fromthe forming station. The longitudinal cut separates the first, upperline of containers 4, in which the apertures are upwardly-facing, fromthe second, lower line of containers 5, in which the apertures aredownwardly-facing. The first line of containers 4 proceeds, after thecut, following the advancement line normally, which brings it to thefiling station, while the second line is tilted by 180° by the tilingdevice 1 which also aligns the second line with the first line, so thatthe two lines proceed parallel to one another towards the fillingstation, both with their apertures facing upwards in order to receivethe product which is to be put into the containers.

Arrows F indicate the advancement direction of the containers 4 and 5along the advancement line which goes from the forming station to thefilling station.

The tilting device 1 of the strip of containers 5 comprises three drumguides, respectively 6, 7 and 8, about which the transiting strip windsin sequence. Each drum guide comprises a wheel freely rotatable about anaxis thereof and laterally provided with two opposite borders 9, forlaterally containing the strip. The strip winds about each guide with aflat side of the strip oriented parallel to the rotation axis of theguide.

FIG. 4 shows any one of the three guides, having a lateral surface whichin section is conformed complementarily to the container strip. Thelateral surface comprises at its centre a concave annular part 10,thanks to which the containers are not subject to deformation, whichannular part 10 is predisposed to receive the main body of thecontainers; the annular part 10 may be in the shape of a continuousgullet or can be a series of recesses arranged circumferentially andequidistanced one from another at a distance which is equal to the stepof the containers on the strip. The lateral surface of the guidesfurther comprises two annular end surfaces 11 and 12, of unequaldiameters, one of which is predisposed to receive the welded part of thestrip which does not comprise a container, and the other of which ispredisposed to receive the part of the strip comprising the containermouths, which terminate in the apertures. The mouths of the containerscan be located in cavities arranged circumferentially on the annular endsurface 12 of the guide at reciprocal distances equal to the step of themouths.

The first guide 6 is located close to the advancement line F of thestrip having a winding axis perpendicular to the advancement line andarranged vertically. The first guide 6 causes the strip to deviate byabout 90° (in the case of FIG. 1, towards the left) with respect to thenormal line of advancement F.

The second guide 7, which is situated by the side of and at a certaindistance from the line of advancement F, exhibits a winding axis whichis parallel to the line of advancement F. The strip, in passing from thefirst guide 6 to the second guide 7, is twisted on itself (in theillustrated embodiment by about 90°) so that the containers pass from avertical configuration, with the apertures facing downwards, to ahorizontal configuration, with the apertures facing forwards. The stripexits from the second guide 7 in an opposite direction with respect tothe entrance direction, after having rotated by 180° about the axis ofthe drum, with the containers horizontal and the apertures facingforwards.

The third guide 8, which is located in proximity of the line ofadvancement F, slightly more forwards than the fist guide 6, exhibits awinding axis which is perpendicular to the line of advancement. Thethird guide 8, which is very close to the first guide 6, is situatedslightly higher and to the left of the first guide 6, so that the stripof containers 5 exiting from the third guide 8 comes to be side-by-side,parallel and at the same height as the other strip of containers 4 whichproceeds normally along the line of advancement F, with the sameorientation as before. As its passes from the second guide 7 to thethird guide 8 the strip of containers 5 twists on itself (by about 90°in the present embodiment) so that the containers are brought from thehorizontal position to a vertical configuration, with the aperturesfacing upwards. The strip of containers 5 enters the third guide 8 in amore-or-less perpendicular direction to the line of advancement F andwhen the strip exits from the third guide 8, after winding by about aquarter of a full turn around the vertical axis of the drum, comes to beon the line of advancement F, paired with the other strip.

The position of the second guide 7 can be adjusted in at least onedirection G transversal to the line of advancement F, so that the timingof the two paired lines of containers 4 and 5 can be adjusted on exitfrom the tilting device.

The winding axes of the first guide 6 and the third guide 8 are parallelto each other and parallel to the lie (in this case vertical) of theflat part of the strip transiting along the main line of advancement F.The winding axis of the second guide 7 is perpendicular to the axes ofthe other two guides 6 and 8.

During operation, in a first stage, in which the device 11 is readied,the first tract of the strip of containers 5 is manually wound onto thethree guides 6, 7 and 8, rotating and twisting the strip in theabove-described way. Then, once the strip has been engaged on thedrawing means (of known type and not illustrated), which cause the stripto advance (generally in step-motion), the device is ready to functionautomatically.

In a further embodiment, not illustrated, the winding guides, which inthe illustrated embodiment comprise freely-rotatable drums or pulleys,can be constituted by fixed cylindrical elements. It is howeverpreferable that at least the second guide 7 comprises a rotatableelement 7. Further, at least one of the wheels or pulleys (preferablythe second) can be a drive pulley and be provided, on its surface, withmeans for drawing the strip, such as for example cogs (which could beconformed similarly to the containers), or an external high-frictionsurface, or both solutions together.

The change in orientation of the strip of containers 5 is made when thestrip is in transversally deviated path with respect to the main line ofadvancement F. The space occupied in a longitudinal direction (accordingto the main axis of advancement of the strip towards the fillingstation) in order to carry out the twisting operation is reduced to aminimum, indeed is practically eliminated. Even the space occupied in atransversal direction is relatively small. With this solution theforming and filling of the containers 4 and 5 occupies a relativelycontained space, especially lengthwise.

In the present embodiment described, a strip of containers is tiltedstarting from a configuration in which the flat part of the strip isvertically arranged. The tilting device can however be applied in caseswhere the starting configuration is different, for example with the flatpart horizontally arranged.

The tilting device can also be used with strips of containers made fromone film only of heat-formable plastic material (of known type). In thiscase the containers are open trays, open on one side with the openingsarranged on the flat side of the strip and turned the same way, and not,as in the previously-illustrated case, arranged on the edge of the stripand turned on opposite sides. In this case too, the machine can comprisea heat-forming station in which, on the same strip of plastic material,two paired and symmetrical lines of containers are formed; after formingone of the two lines is tilted by 180° and superimposed on the otherline. To favour tilting it is preferable first to make a longitudinalcut between the two lines.

The tilting device and process can be applied on a machine which formsstrips of containers composed of a single line of containers.

A machine, for example a forming, filing and sealing machine, cancomprise one or even a plurality of tilting devices, should it benecessary to tilt the strip of containers once, twice or more times in asame machine.

1-10. (canceled)
 11. A device for tilting a continuous strip ofcontainers made of heat-formable material, in which the containers arearranged in a line, one behind another, and the strip of containers isadvanced along a predetermined line of advance, comprising three windingguides about which the transiting strip winds in sequence; the stripwinds about each guide with a flat part of the strip oriented parallelto an axis of the guide; a first guide of the three guides being locatedin proximity of the line of advance of the strip with a winding axiswhich is perpendicular to the line of advance; a second guide of thethree guides being located laterally and distant from the line ofadvance, with a winding axis which is parallel to the line of advance; athird guide of the three guides being located in proximity of the lineof advance, slightly forward of the first guide, with a winding axiswhich is perpendicular to the line of advance.
 12. The device accordingto claim 11, wherein at least one of the winding guides comprises a drumwhich is freely rotatable about an axis thereof.
 13. The deviceaccording to claim 11, wherein a position of the second guide of thethree guides is adjustable at least in a transverse direction to theline of advance.
 14. The device according to claim 11, wherein eachwinding guide comprises two opposite rims for lterally containing thefirst strip of containers.
 15. A machine for forming and fillingcontainers made of a heat-formable material, comprising: a line forfeeding at least one strip of film made of a heat-formable plasticmaterial; a heat-forming station in which at least one strip ofcontainers is formed; a tilting device for tilting the at least onestrip of containers; and a filling station for the containers.